Metal-ceramic composite material and method for forming the same

ABSTRACT

A metal-ceramic composite material and a method for forming the same are provided. The metal-ceramic composite material includes a metal body, a plurality of metal oxide nanoparticles and a plurality of ceramic particles. The metal body includes a metal material having a first surface energy. The metal oxide nanoparticles and the ceramic particles are dispersed in the metal body. The ceramic particles have a second surface energy that is higher than the first surface energy.

TECHNICAL FIELD

The present disclosure relates to a metal-ceramic composite material anda method for forming a metal-ceramic composite material.

BACKGROUND

Due to fuel prices going up and environmental issues such as energyconservation and carbon reduction, Europe launched a project called theClean Sky JTI (Joint Technology Initiative) in 2008 to improve thetechnological performance of aircraft and air transportation in Europe.The project aims to define the developmental direction of the aviationindustry in the future, including reduction of fuel consumption andreduction of noise, such as reducing carbon emissions by 50% fornext-generation aircraft, reducing carbon monoxide emissions by 80%, andreducing engine noise by 50%, and these specific targets are expected tobe achieved by 2020. In this regard, lightweight components can be usedto reduce weight and improve flight efficiency. The development oflightweight materials and structural designs has recently become themain focus of this effort.

In addition to the development of lightweight components in aerospacetechnology, the automobile industry has gradually turned to adoptinglightweight components in engine systems. For example, lightweightcomponents are expected to be utilized in an impeller with a complicatedshape in an automobile turbocharger system in order to improve theoperating efficiency.

Lightweight components used in either aerospace technology or theautomobile industry are required to have excellent mechanicalproperties, such as tensile strength, hardness, rigidity, etc.

Therefore, with the increasing needs described above, researchers havebeen working on developments and improvements of lightweight componentshaving the desired mechanical properties.

SUMMARY

The present disclosure relates to a metal-ceramic composite material anda method for forming a metal-ceramic composite material. In theembodiments, in the metal-ceramic composite material, the metal oxidenanoparticles dispersed in the metal body enhance the compatibilitybetween the metal material having a relatively low surface energy andthe ceramic particles having a relatively high surface energy. This way,the ceramic particles can be dispersed in the metal body more uniformly.The hardness of the metal-ceramic composite material can effectively beimproved, and the mechanical strength and rigidity of the metal-ceramiccomposite material can be increased.

According to an embodiment of the present disclosure, a metal-ceramiccomposite material is provided. The metal-ceramic composite materialincludes a metal body, a plurality of metal oxide nanoparticles, and aplurality of ceramic particles. The metal body includes a metal materialhaving a first surface energy. The metal oxide nanoparticles and theceramic particles are dispersed in the metal body. The ceramic particleshave a second surface energy that is higher than the first surfaceenergy.

According to another embodiment of the present disclosure, a method forforming a metal-ceramic composite material is provided. The methodincludes the following steps: mixing a metal starting material and aplurality of ceramic particles to form a mixture, wherein the metalstarting material comprises a metal powder and a metal oxide interlayerformed on the surface of the metal powder, the metal powder comprises ametal material having a first surface energy, and the ceramic particleshave a second surface energy that is higher than the first surfaceenergy; performing a pretreatment on the mixture to form a pretreatedmixture, wherein the ceramic particles are attached to the metal oxideinterlayer in the pretreated mixture; and performing a fabricationprocess on the pretreated mixture to form the metal-ceramic compositematerial.

To further simplify and clarify the foregoing contents and otherobjects, characteristics, and merits of the present disclosure, adetailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a schematic drawing of a metal-ceramic composite materialaccording to an embodiment of the present disclosure;

FIG. 1B is an enlarged view of the region 1B in FIG. 1A;

FIG. 2 shows a schematic drawing of a metal starting material accordingto an embodiment of the present disclosure;

FIG. 3 shows a schematic drawing of a pretreated mixture according to anembodiment of the present disclosure;

FIG. 4A to FIG. 4C show imaging contrast in SEM pictures ofmetal-ceramic composite materials according to some embodiments of thepresent disclosure;

FIG. 5 shows an X-ray diffraction pattern of a metal-ceramic compositematerial according to an embodiment of the present disclosure; and

FIG. 6 shows a TEM picture of a metal-ceramic composite materialaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

In the embodiments of the present disclosure, in the metal-ceramiccomposite material, the metal oxide nanoparticles dispersed in the metalbody enhance the compatibility between the metal material having arelatively low surface energy and the ceramic particles having arelatively high surface energy, so that the ceramic particles can bedispersed in the metal body more uniformly. In this manner, the hardnessof the metal-ceramic composite material can effectively be improved, andthe mechanical strength and rigidity of the metal-ceramic compositematerial can be increased. Details of embodiments of the presentdisclosure are described hereinafter with accompanying drawings.Specific structures and compositions disclosed in the embodiments areused as examples and for explaining the disclosure only and are not tobe construed as limitations. A person having ordinary skill in the artmay modify or change corresponding structures and compositions of theembodiments according to actual application.

Unless explicitly indicated by the description, as used herein, thesingular forms “a,” “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It shouldbe further understood that when such as the term “comprises” and/or“comprising,” is used in this specification, it specifies the presenceof described features, steps, operations, elements, and/or components,but does not preclude the presence or addition of one or more otherfeatures, steps, operations, elements, components, and/or groupsthereof.

Throughout this specification, the term “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the phrases “in one embodiment” or “inan embodiment” in various contexts throughout this specification do notnecessarily all refer to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments. It should be appreciatedthat the following figures are not drawn to scale; rather, these figuresare merely illustrations.

FIG. 1A shows a schematic drawing of a metal-ceramic composite material10 according to an embodiment of the present disclosure, and FIG. 1B isan enlarged view of the region 1B in FIG. 1A. As shown in FIGS. 1A-1B,the metal-ceramic composite material 10 includes a metal body 100, aplurality of metal oxide nanoparticles 200, and a plurality of ceramicparticles 300. The metal body 100 includes a metal material having afirst surface energy. The metal oxide nanoparticles 200 and the ceramicparticles 300 are dispersed in the metal body 100. The ceramic particles300 have a second surface energy that is higher than the first surfaceenergy.

According to the embodiments of the present disclosure, the metal oxidenanoparticles 300 dispersed in the metal body 100 enhance thecompatibility between the metal material having a relatively low surfaceenergy and the ceramic particles 300 having a relatively high surfaceenergy, so that the ceramic particles 300 can be dispersed in the metalbody 100 more uniformly. This effectively improves the hardness of themetal-ceramic composite material 10 and increases the mechanicalstrength and rigidity of the metal-ceramic composite material 10.

In some embodiments, the metal material having the first surface energymay include metal or an alloy. For example, in some embodiments, themetal material having the first surface energy may include aluminum(Al), copper (Cu), iron (Fe), silicon (Si), cobalt (Co), lead (Pb), analloy of any of the above metals, or any combination of the above.

In the embodiments, the ceramic particles 300 may include siliconcarbide (SiC), tungsten carbide (WC), or a combination thereof. In someembodiments, as shown in FIGS. 1A-1B, the ceramic particles 300 may havea particle size D1 of about 0.5 μm to about 20 In some embodiments, asshown in FIGS. 1A-1B, the ceramic particles 300 may have a particle sizeD1 of about 1 μm to about 10 In some embodiments, as shown in FIGS.1A-1B, the ceramic particles 300 may have a particle size D1 of about 2μm to about 5 μm.

According to some embodiments of the present disclosure, the particlesize D1 of the ceramic particles 300 is relatively small, such as equalto or less than 10 μm. As such, there can be a relatively large numberof the ceramic particles 300 dispersed in a unit volume of the metalbody 100, resulting in a better dispersion of the ceramic particles 300within the microstructure of the metal body 100. The metal-ceramiccomposite material 10 can be strengthened more effectively and uniformlyby the ceramic particles 300.

In the embodiments, the metal oxide nanoparticles 200 may includealuminum oxide, copper oxide, iron oxide, silicon oxide, cobalt oxide,lead oxide, or any combination of the above. In some embodiments, asshown in FIG. 1B, the metal oxide nanoparticles 200 may have a particlesize D2 of about 3 nm to about 50 nm.

In some embodiments, the metal oxide nanoparticles 200 may be formed ofa native oxide of the metal material having the first surface energy.For example, in some embodiments, the metal material may be aluminum,and the metal oxide nanoparticles 200 may be aluminum oxidenanoparticles.

In some embodiments, the first surface energy may be less than 1.5 J/m²,and the second surface energy may be higher than 2 J/m². Accordingly, insome embodiments, the difference between the first surface energy andthe second surface energy is higher than 0.5 J/m².

In some embodiments, the first surface energy may be less than 1.0 J/m²,and the second surface energy may be higher than 2.5 J/m². Accordingly,in some embodiments, the difference between the first surface energy andthe second surface energy is higher than 1.5 J/m².

In some embodiments, the metal material of the metal body 100 may bealuminum or an aluminum alloy having a surface energy of about 0.84J/m². In some embodiments, the metal material of the metal body 100 maybe silicon having a surface energy of about 1.24 J/m².

In some embodiments, the ceramic particles 300 may be silicon carbideparticles having a surface energy of about 3.2 J/m². In someembodiments, the ceramic particles 300 may be tungsten carbide particleshaving a surface energy of about 1.6 J/m² to 8.7 J/m².

In some embodiments, the metal oxide nanoparticles 200 have a thirdsurface energy, and a difference between the second surface energy andthe third surface energy may be less than 1 J/m². In some otherembodiments, the difference between the second surface energy and thethird surface energy may be less than 0.5 J/m².

According to some embodiments of the present disclosure, the relativelysmall difference between the surface energies of the metal oxidenanoparticles 200 and the ceramic particles 300 is advantageous to theinteraction and bonding between the metal oxide nanoparticles 200 andthe ceramic particles 300, and the interaction and bonding make iteasier for the ceramic particles 300 to be dispersed within the metalbody 100 with the help from the metal oxide nanoparticles 200. As aresult, according to some embodiments of the present disclosure, thesmaller the difference between the second surface energy and the thirdsurface energy is, the better enhancement of the compatibility betweenthe metal material and the ceramic particles 300 can be provided fromthe metal oxide nanoparticles 200.

In some embodiments, the metal oxide nanoparticles 200 may be aluminumoxide nanoparticles having a surface energy of about 2.0 J/m² to 4.0J/m².

In some embodiments, as shown in FIGS. 1A-1B, the metal-ceramiccomposite material 10 has grains 10A and grain boundaries 10B, and themetal oxide nanoparticles 200 may be formed within the grain boundaries10B. In some embodiments, more specifically, a portion of the metaloxide nanoparticles 200 may be formed within the grain boundaries 10B,while another portion of the metal oxide nanoparticles 200 may be bondedto the ceramic particles 300 dispersed in the grains 10A.

In some embodiments, the metal oxide nanoparticles 200 may be present inthe amount of less than about 2 vol. % of the metal-ceramic compositematerial 10. In some embodiments, the metal oxide nanoparticles 200 maybe present in the amount of less than about 1 vol. % of themetal-ceramic composite material 10. In some embodiments, the metaloxide nanoparticles 200 may be present in the amount of about 0.1 vol. %to 1 vol. % of the metal-ceramic composite material 10.

According to some embodiments of the present disclosure, if the metaloxide nanoparticles 200 are present in the amount of above 2 vol. % ofthe metal-ceramic composite material 10, the whole structure of themetal-ceramic composite material 10 may be too brittle, due to therebeing too many metal oxide nanoparticles 300. This may result in reducedmechanical strength of the metal-ceramic composite material 10. Thus,the metal oxide nanoparticles 200 present in the amount of about 0.1vol. % to 1 vol. % of the metal-ceramic composite material 10 canimprove the compatibility between materials of the metal body 100 andthe ceramic particles 300 without deteriorating the mechanicalproperties of the metal-ceramic composite material 10.

In some embodiments, the metal oxide nanoparticles 300 and the metalmaterial having the first surface energy in total may be present in theamount of about 70-97 vol. % of the metal-ceramic composite material 10.

In some embodiments, the ceramic particles 300 may be present in theamount of about 3-30 vol. % of the metal-ceramic composite material 10.

According to some embodiments of the present disclosure, if the amountof the ceramic particles 300 is less than 3 vol. % of the metal-ceramiccomposite material 10, the as-formed metal-ceramic composite material 10may have reduced mechanical strength and rigidity. If the amount of theceramic particles 300 exceeds 30 vol. % of the metal-ceramic compositematerial 10, despite largely increasing the rigidity, the as-formedmetal-ceramic composite material 10 may have reduced tensile strength.As such, the ceramic particles 300 present in the amount of 3-30 vol. %of the metal-ceramic composite material 10 can provide excellentmechanical strength and rigidity as well as increased tensile strengthfor the metal-ceramic composite material 10.

According to the embodiments of the present disclosure, a method forforming a metal-ceramic composite material 10 is provided.

According to the embodiments of the present disclosure, the method forforming the metal-ceramic composite material 10 includes mixing a metalstarting material 20 and a plurality of ceramic particles 300 to form amixture, and performing a pretreatment on the mixture to form apretreated mixture 30.

FIG. 2 shows a schematic drawing of a metal starting material 20according to an embodiment of the present disclosure, and FIG. 3 shows aschematic drawing of a pretreated mixture 30 according to an embodimentof the present disclosure. The elements in the present embodimentsharing similar or the same labels with those in the previous embodimentare similar or the same elements, and the description of which isomitted.

In the embodiments, as shown in FIG. 2, the metal starting material 20includes a metal powder 220 and a metal oxide interlayer 210 formed onthe surface 220A of the metal powder 220, and the metal powder 220includes a metal material having a first surface energy. In theembodiments, the second surface energy of the ceramic particles 300 ishigher than the first surface energy of the metal material of the metalpowder 220. The details of the metal material having the first surfaceenergy and the ceramic particles 300 having the second surface energyare as described above and not repeated here.

In the embodiments, as shown in FIG. 3, after performing thepretreatment, the ceramic particles 300 are attached to the metal oxideinterlayer 210 in the pretreated mixture 30.

Currently, a reinforcing phase material is usually mixed with a metalmaterial by stirring at elevated temperatures to form a reinforcingmetal melt for forming a reinforced metal material. However, the largedifference between the surface energies of the reinforcing phasematerial and the metal material leads to particle aggregations formed inthe melt and poor dispersion of the reinforcing phase material. Evenwith high-speed stirring, only the reinforcing phase material with alarge particle size may be dispersed within the melt, and this methodalso suffers from problems of high-speed stirring introducing a largeamount of oxides formed on the surface of the melt into the reinforcingmetal melt and undesirably increasing the viscosity of the reinforcingmetal melt. The increased viscosity and oxygen content aredisadvantageous to the following fabrication process as well as themechanical properties of the as-formed reinforced metal material.

According to the embodiments of the present disclosure, the metal oxideinterlayer 210 is formed on the surface 220A of the metal powder 220, sothat the ceramic particles 300 can easily be in contact with the metaloxide interlayer 210 of the metal starting material 20 in the mixture;then, after the pretreatment is performed, the ceramic particles 300 aredriven to be attached, e.g. through chemical bonding, to the metal oxideinterlayer 210 and/or the fragments of the metal oxide interlayer 210 ofthe metal starting material 20 in the pretreated mixture 30, since themetal powders 220 are nicely dispersed in the pretreated mixture 30, theceramic particles 300 along with the metal oxide interlayers 210 and/orthe fragments of the metal oxide interlayer 210 on the metal powders 220are thereby nicely dispersed within the pretreated mixture 30. As aresult, the metal oxide interlayer 210 enhances the compatibilitybetween the metal material having a relatively low surface energy andthe ceramic particles 300 having a relatively high surface energy. Assuch, with the design of the mixture as well as the pretreatment stepaccording to the embodiments of the present disclosure, the pretreatedmixture 30, in which the ceramic particles 300 are uniformly dispersedwithin the metal material, is provided with good mechanical strength andrigidity and is ready for following fabrication processes.

In some embodiments, as shown in FIG. 2, the metal oxide interlayer 210may be formed of a native oxide of the metal powder 220. For example, insome embodiments, the metal oxide interlayer 210 may be formed of anoxide of the metal material having the first surface energy. Theexamples of the material of the metal oxide interlayer 210 are basicallythe same as those described above for the metal oxide nanoparticles 200,and the details are not repeated here.

In some embodiments, as shown in FIG. 3, the ceramic particles 300 mayhave a particle size D1 of about 0.5 μm to about 20 about 1 μm to about10 or about 2 μm to about 5 μm.

In some embodiments, the metal oxide interlayer 210 may have a thirdsurface energy, and a difference between the second surface energy andthe third surface energy may be less than 1 J/m².

According to some embodiments of the present disclosure, the differencebetween the second surface energy of the ceramic particles 300 and thethird surface energy of the metal oxide interlayer 210 is relativelysmall, e.g. less than 1 J/m², and the surface 220A of the metal powder220 is covered by the metal oxide interlayer 210, allowing the metalstarting material 20 and the ceramic particles 300 to have similarsurface energies, preventing particle aggregation upon mixing and/orstirring, and providing a more uniform dispersion of the metal startingmaterial 20 and the ceramic particles 300. This allows the introductionof the ceramic particles 300 with a relatively small particle size D1,which results in a better dispersion of the ceramic particles 300 withinthe microstructure of the metal material.

In some embodiments, as shown in FIG. 2, the metal oxide interlayer 210may have a thickness T1 of about 5 nm to about 7 nm.

In some embodiments, as shown in FIG. 2, the metal powder 220 may have aparticle size D3 of about 10 μm to about 300 In some embodiments, asshown in FIG. 2, the metal powder 220 may have a particle size D3 ofabout 200 μm to about 300 μm.

According to some embodiments of the present disclosure, the thicknessT1 of the metal oxide interlayer 210 is relatively thin, limiting thevolume of the metal oxide involved in the pretreatment and formed in thepretreated mixture 30, so as not to generate any unwanted phases in thepretreated mixture 30. Accordingly, the mechanical properties of thepretreated mixture 30 as well as the as-formed metal-ceramic compositematerial 10 are not affected by an unwanted phase. Furthermore, therelatively thin thickness T1 of the metal oxide interlayer 210 limitsthe amount of metal oxides present in the metal-ceramic compositematerial 10, which prevents the whole structure of the metal-ceramiccomposite material 10 from being too brittle—a condition caused by toomuch metal oxide. Thereby, the mechanical properties of themetal-ceramic composite material 10 are not affected.

In addition, according to some embodiments of the present disclosure,the particle size D1 of the ceramic particles 300 is relatively small,e.g. equal to or less than 10 μm. The particle size D3 of the metalpowder 220 is relatively large, e.g. about 200 μm to about 300 Moreceramic particles 300 can be attached to the metal oxide interlayer 210formed on the metal powder 220, and thus a more uniform dispersion ofthe ceramic particles 300 is achieved.

In some embodiments, the metal starting material 20 may be present inthe amount of about 70-97 vol. % of the mixture.

In some embodiments, the ceramic particles 300 may be present in theamount of about 3-30 vol. % of the mixture.

In some embodiments, the pretreatment may include heating, pressurizing,or a combination thereof, but the present disclosure is not limitedthereto.

In some embodiments, performing the pretreatment may include heating themixture at about 400° C. to about 500° C. for about 2 hours to 4 hours.In some embodiments, the pretreatment may be performed under a pressureof about 200-500 Pa.

According to some embodiments of the present disclosure, if thepretreatment is performed at a temperature of lower than 400° C., thepretreatment reaction may not be fully completed, and there may be lessattachment and/or the chemical bonding formed between the ceramicparticles 300 and the metal oxide interlayer 210 (and/or the fragmentsof the metal oxide interlayer 210); if the pretreatment is performed ata temperature of above 500° C., the metal material would melt quickly,resulting in less attachment and/or the chemical bonding formed betweenthe ceramic particles 300 and the metal oxide interlayer 210 (and/or thefragments of the metal oxide interlayer 210). Therefore, according tosome embodiments of the present disclosure, performing the pretreatmentby heating the mixture at about 400° C. to about 500° C. provides moreattachment and/or the chemical bonding formed between the ceramicparticles 300 and the metal oxide interlayer 210 (and/or the fragmentsof the metal oxide interlayer 210), and thus the resulting dispersion ofthe ceramic particles 300 is further enhanced.

Next, according to the embodiments of the present disclosure, the methodfor forming the metal-ceramic composite material 10 further includesperforming a fabrication process on the pretreated mixture 30 to formthe metal-ceramic composite material 10.

In some embodiments, the fabrication process may include a gasatomization process, a pouring casting process, a continuous castingprocess, a die casting process, a vacuum casting process, a low-pressurecasting process, an additive manufacturing process, or any combinationthereof, but the present disclosure is not limited thereto.

According to some embodiments of the present disclosure, themetal-ceramic composite material 10 may be a bulk material or a powdermaterial. In some embodiments, for example, a gas atomization processcan be performed on the pretreated mixture 30 to form the metal-ceramiccomposite material 10 as a powder material, and a 3D object may befurther formed from the powder material by an additive manufacturingprocess. In some embodiments, a casting process can be performed on thepretreated mixture 30 to form the metal-ceramic composite material 10 asa bulk material.

Further explanation is provided with the following examples.Compositions of metal-ceramic composite materials and measurements ofproperties of the metal-ceramic composite materials are listed forshowing the properties of the metal-ceramic composite materialsaccording to the embodiments of the disclosure. However, the followingexamples are for purposes of describing particular embodiments only, andare not intended to be limiting.

EXAMPLES Preparation of a Pretreated Mixture [Pretreated Mixture 1]

95 vol. % of an aluminum starting material (an aluminum oxide layerhaving a thickness of about 5-7 nm covered on each aluminum powderhaving a particle size of about 1-150 μm, and 5 vol. % of siliconcarbide (SiC) particles having a particle size of about 2-5 μm aremixed, then the mixture is heated at 450° C. for 3 hours under apressure of about 100 Pa and then cooled to room temperature, and thenthe pretreated mixture 1 of aluminum-silicon carbide composite materialis obtained.

[Pretreated Mixtures 2-3]

The preparation of pretreated mixtures 2 and 3 is similar to that ofpretreated mixture 1, with the only difference being the volume ratiosof the aluminum starting material to the silicon carbide particles. Thepretreated mixture 2 includes 92 vol. % of aluminum starting materialand 8 vol. % of silicon carbide (SiC) particles, and the pretreatedmixture 3 includes 89 vol. % of aluminum starting material and 11 vol. %of silicon carbide (SiC) particles.

Examples 1-3

The pretreated mixture is heated to a temperature above the meltingpoint of the aluminum powder to form an aluminum-silicon carbidecomposite melt, and then aluminum-silicon carbide composite particlesare formed from the aluminum-silicon carbide composite melt by gasatomization. The morphology and composition of the as-formed particlesare characterized by SEM.

FIG. 4A to FIG. 4C show imaging contrast in SEM pictures ofmetal-ceramic composite materials according to some embodiments of thepresent disclosure, and FIG. 5 shows an X-ray diffraction pattern of ametal-ceramic composite material according to an embodiment of thepresent disclosure. More specifically, FIG. 4A shows the silicon carbidecoverage of an aluminum-silicon carbide composite particle of Example 1,FIG. 4B shows the silicon carbide coverage of an aluminum-siliconcarbide composite particle of Example 2, FIG. 4C shows the siliconcarbide coverage of an aluminum-silicon carbide composite particle ofExample 3, and FIG. 5 shows the X-ray diffraction pattern of thealuminum-silicon carbide composite particles of Example 3.

As shown in FIG. 4A, the silicon carbide coverage is about 4.1% to 5.2%,which is almost the same as the volume ratio of the silicon carbideaddition (5 vol. %). As shown in FIG. 4B, the silicon carbide coverageis about 8% to 8.8%, which is almost the same as the volume ratio of thesilicon carbide addition (8 vol. %). As shown in FIG. 4C, the siliconcarbide coverage is about 11%, which is basically the same as the volumeratio of the silicon carbide addition (11 vol. %).

As shown in FIG. 5, the XRD pattern shows that the aluminum-siliconcarbide composite particles of Example 3 do not form any unwantedcrystalline phase except for the expected crystalline phases ofaluminum, silicon, and silicon carbide.

An additive manufacturing process is further performed on thealuminum-silicon carbide composite particles of Example 2 to form a 3Dobject. The mechanical properties and morphology of the 3D object formedfrom the aluminum-silicon carbide composite particles of Example 2 arecharacterized, the results are shown in table 1 and FIG. 6, andmechanical properties of some commercial available comparative examplesare also shown in table 1 for comparison.

FIG. 6 shows a TEM picture of a metal-ceramic composite materialaccording to an embodiment of the present disclosure. More specifically,FIG. 6 shows the TEM picture of a 3D object formed from thealuminum-silicon carbide composite particles of Example 2 by an additivemanufacturing process.

As shown in FIG. 6, the microstructure of the aluminum-silicon carbidecomposite 3D object has grains and grain boundaries, and the brightspots within the grain boundaries, proven by TEM diffraction patterns(not shown herein), are aluminum oxide nanoparticles.

TABLE 1 3D object from Comparative Comparative Example 2 example 1example 2 Material Aluminum-silicon EN AW-6082 T6 A359 aluminum carbidecomposite aluminum alloy alloy mixed with particles of Example 2 20 wt %of SiC Fabrication process Additive Forging O'Fallon castingmanufacturing Yield strength 390 370 303 (MPa) Ultimate tensile 445 400359 strength (MPa) Elongation rate (%) 3 15 <1 Hardness HRB 85 (162 HBW)— — Young's modulus ~85 70 99 (GPa)

As shown in table 1, the object of Comparative example 1 does notcontain any silicon carbide material. Despite its high yield strengthand high ultimate tensile strength, the low Young's Modulus of 70 GPaindicates that its rigidity is too low.

In addition, while the object of Comparative example 2 contains 20 wt %of silicon carbide, the object of Comparative example 2 is neitherformed of a metal-ceramic composite material according to theembodiments of the present disclosure, nor formed by a method accordingto the embodiments of the present disclosure. As indicated in table 1,the object of Comparative example 2 has high rigidity, but theelongation rate is too low, which may cause the object to break suddenlywithout warning when a very low tensile force is applied, raising safetyconcerns.

As shown in table 1, the 3D object formed from Example 2 is providedwith excellent yield strength, ultimate tensile strength, hardness, andrigidity as well as a proper elongation rate, so that the 3D object hasexcellent mechanical properties with minimum safety concerns.

While the disclosure has been described by way of example and in termsof the exemplary embodiments, it should be understood that thedisclosure is not limited thereto. On the contrary, it will be apparentto those skilled in the art that various modifications and variationscan be made to the disclosed embodiments. It is intended that thespecification and examples be considered as exemplary only, with a truescope of the disclosure being indicated by the following claims andtheir equivalents.

What is claimed is:
 1. A metal-ceramic composite material, comprising: ametal body comprising a metal material having a first surface energy; aplurality of metal oxide nanoparticles dispersed in the metal body; anda plurality of ceramic particles dispersed in the metal body, whereinthe ceramic particles have a second surface energy higher than the firstsurface energy.
 2. The metal-ceramic composite material as claimed inclaim 1, wherein the first surface energy is less than 1.5 J/m², and thesecond surface energy is higher than 2 J/m².
 3. The metal-ceramiccomposite material as claimed in claim 1, wherein the metal oxidenanoparticles have a third surface energy, and a difference between thesecond surface energy and the third surface energy is less than 1 J/m².4. The metal-ceramic composite material as claimed in claim 1, whereinthe ceramic particles have a particle size of 0.5 μm to 20 μm.
 5. Themetal-ceramic composite material as claimed in claim 1, wherein themetal oxide nanoparticles have a particle size of 3 nm to 50 nm.
 6. Themetal-ceramic composite material as claimed in claim 1, wherein themetal oxide nanoparticles are present in an amount of less than 1 vol. %of the metal-ceramic composite material.
 7. The metal-ceramic compositematerial as claimed in claim 1, wherein the metal oxide nanoparticlesare formed of a native oxide of the metal material having the firstsurface energy.
 8. The metal-ceramic composite material as claimed inclaim 7, wherein the metal-ceramic composite material has grains andgrain boundaries, and the metal oxide nanoparticles are formed withinthe grain boundaries.
 9. The metal-ceramic composite material as claimedin claim 1, wherein the metal oxide nanoparticles and the metal materialhaving the first surface energy in total are present in an amount of70-97 vol. % of the metal-ceramic composite material.
 10. Themetal-ceramic composite material as claimed in claim 1, wherein theceramic particles are present in an amount of 3-30 vol. % of themetal-ceramic composite material.
 11. The metal-ceramic compositematerial as claimed in claim 1, wherein the metal material having thefirst surface energy comprises aluminum, copper, iron, silicon, cobalt,lead, or a combination thereof, and the ceramic particles comprisesilicon carbide, tungsten carbide, or a combination thereof.
 12. Amethod for forming a metal-ceramic composite material, comprising:mixing a metal starting material and a plurality of ceramic particles toform a mixture, wherein the metal starting material comprises a metalpowder and a metal oxide interlayer formed on the surface of the metalpowder, the metal powder comprises a metal material having a firstsurface energy, and the ceramic particles have a second surface energyhigher than the first surface energy; performing a pretreatment on themixture to form a pretreated mixture, wherein the ceramic particles areattached to the metal oxide interlayer in the pretreated mixture; andperforming a fabrication process on the pretreated mixture to form themetal-ceramic composite material.
 13. The method for forming themetal-ceramic composite material as claimed in claim 12, wherein themetal oxide interlayer is formed of a native oxide of the metal powder,and the metal oxide interlayer has a thickness of 5 nm to 7 nm.
 14. Themethod for forming the metal-ceramic composite material as claimed inclaim 12, wherein the pretreatment comprises heating, pressurizing, or acombination thereof.
 15. The method for forming the metal-ceramiccomposite material as claimed in claim 12, wherein performing thepretreatment comprises heating the mixture at 400° C. to 500° C. for 2hours to 4 hours.
 16. The method for forming the metal-ceramic compositematerial as claimed in claim 12, wherein the fabrication processcomprises a gas atomization process, a pouring casting process, acontinuous casting process, a die casting process, a vacuum castingprocess, a low-pressure casting process, an additive manufacturingprocess, or any combination thereof.
 17. The method for forming themetal-ceramic composite material as claimed in claim 12, wherein thefirst surface energy is less than 1.5 J/m², and the second surfaceenergy is higher than 2 J/m².
 18. The method for forming themetal-ceramic composite material as claimed in claim 12, wherein theceramic particles have a particle size of 0.5 μm to 20 μm.
 19. Themethod for forming the metal-ceramic composite material as claimed inclaim 12, wherein the metal starting material is present in an amount of70-97 vol. % of the mixture.
 20. The method for forming themetal-ceramic composite material as claimed in claim 12, wherein theceramic particles are present in an amount of 3-30 vol. % of themixture.